Welcome to the FAQ’s

This section lists some of the many questions Retrofit Academy staff and tutors have been asked over the years.

The below DPC and the extension of the roofline are best practice from the standard. I have been told that we do not have to do it, but it will change the risk assessment. Would this risk really stop us from going forward or can we continue without it? Many customers will not continue if they have to do this.

Below DPC insulation and the extension of the rooflines are part of the best practice
details from the industry (NIA/INCA/SWIGA) and compliance with them is required
by PAS 2035 and PAS 2030. Those details come with red, amber and green markers
on them. The red cannot be used, green are recommended; the amber details can
be used but the Inherent Technical Risk in the PAS 2035 risk assessment (Annex B)
goes up by one. If you do not use these details you must show by calculation (see
BRE IP 1/06) that the temperature factors of the thermal bridges at the eaves and at
the floor-wall junction are not less than 0.75.

Is there actually a requirement for the RC to visit the property either during or post install? This was alluded to in the RC training but there does not actually seem to be any requirement around this in the PAS or the process map.

There is no requirement to go
there, but there is nothing to
stop you going there, and a
wise RC would do so. Good
practice would be to ensure
that you do attend, especially
during the installation work,
as a professional obligation.

Can you explain the expected procedure once the assessment has been carried out?

The process, as set out in PAS 2035, is that the Retrofit Coordinator sees the
project first, because the RC has to do the risk assessment before the dwelling
assessment is done. After the assessment, the RC does the improvement
option evaluation and medium-term improvement plan, then the design is done,
based on the first stage of the medium-term plan.

The assessment is not intended to replace a technical survey by the installer, is that right? They are still expected to carry out their own pre installation survey?

Yes, the dwelling assessment
is for the project team to
enable the improvement
option evaluation, medium term plan and design to be
prepared. The pre-insulation
inspection is a requirement of
PAS 2030 for the installer to
carry out to ensure the design is capable
of being installed and to support the
preparation of a method statement.

My understanding is that we can’t use Verge trim AT ALL. We do mainly EWI and going back over our work 60% of it has needed Verge trim. As a coordinator what do we do with these houses. Reject them all? The customer is certainly not going to pay for the roof extension. We’ve only ever had 2 customers do roof work to accommodate the EWI and that’s because they were having a new roof anyway. What about if we can evidence it’s been correctly installed or we can mitigate the risk of water Ingress with lead flashing or a secondary barrier. As a coordinator how should we deal with this issue?

It is true that PAS 2030 and PAS 2035 say you must not use verge trims and so does
the SWIGA guidance, and that is because a huge number of failures we have seen
have come from this. The problem is the seals between sections of trim, which are
usually sealed on installation but the sealant does not withstand thermal movement
and weather, resulting in failure within a relatively short period. Once rainwater
begins to penetrate behind the insulation, the problem becomes very serious and
difficult to remediate. SWIGA is working on something that avoids the use of verge
trims but we don’t as yet have their proposals.

Could we have an update on progress for PAS 2038 for Non Domestic building retrofit?

PAS 2038 should be
published late 2021, possibly
by September

We understand that it is a current requirement to insulate 100% of a park home under PAS2035, or you should not do it at all? If the roof already has some insulation in it, can this section be omitted from the works, if so, what would be deemed to be an adequate level of existing insulation and is there any pattern related to park home standards that would state that all homes built after a certain year would/ should have existing roof insulation?

Park Homes are very high-risk because of the metal in the structure. You need a
proper moisture risk assessment. The access issues to the roof are the same as
they are to the floor. When the PAS is updated (every year) we hope to see Park
Homes included and, also, Enhabit is writing a guide which should be ready for
publication later in 2021.

The flow chart to be followed for <100% IWI jobs (where whole wet rooms may be omitted), is this an ECO-only compromise or is it applicable to Green Homes and Green Homes LAD projects? Whilst 100% installation is undoubtedly "best practise" is it a Green Homes requirement? If so, can it be mitigated as per ECO?

The 100% requirement is
part of the ECO rules, and
also part of the GHG rules.
Mainly relating to kitchens
and bathrooms where the
fittings are in the way, and the
flowchart was developed by
OFGEN for application in ECO
but intended for use in GHG as

As a Retrofit Coordinator with a Level 3 and 4 NDEA qualification, would I be qualified to perform PAS 2038 small buildings, similar to domestic buildings, under PAS 2035, or would I need to complete Level 5?

Yes, Level 3 and 4 NDEA is fine
and you have to be a Retrofit
Coordinator as well.

The ideal time to do a whole house retrofit is during a renovation. If the client has started this and the bathroom or kitchen has already been removed before the Assessor gets there can he/she still undertake the retrofit assessment?

A self-contained unit that has been stripped out ready for retrofit is different from
a dwelling that doesn’t have a kitchen or bathroom. I.e. as long as there is a space
where a kitchen or bathroom will be fitted, that’s different from not having a dedicated
space within a dwelling where they should be. Stripping out the kitchen and/or
bathroom should not inhibit a retrofit assessment.

Is there any guidance in PAS 2035 on Radon risks?

There is no requirement to
deal with Radon risks in PAS
2035 at the moment, although
it is in the training for Retrofit
Coordinator to consider this.

As I understand it, there is currently no vapour-open IWI option available to install under PAS2035 due to the lack of insurance/guarantee, despite the RC training and BS7913 explicitly stating that vapour-open walls (arguably all solid walls) need to use vapour-open insulation? I know this is a big issue, but do you have updates/ insight on this?

Probably not true that all walls need to use vapour-open insulation. Quite a lot have
sand-cement render, or have been repointed with sand-cement mortar, so you need
to look at the walls individually to see if they are still vapour-open, even if they were
when the property was built. Then deciding which way to push-it; towards a more
sealed construction. or push it back to where it used to be; in which case you would
need a vapour-open solution.

Where does it state in PAS 2035 that the Assessor has to provide images of the cavity for a CWI measure?

It doesn’t state that you have
to take photographs, but good
practice would be to never fill a
cavity that you haven’t looked
in, and always to record what
you see. See PAS 2035 clause

If an air permeability test is carried out pre and post install and shows not much has change or the air permeability is leakier than (>)5m3/(h.m2) at50Pa. Is there a requirement under PAS-2035 to upgrade the properties ventilation and if Yes, what would be the requirement?

First of all, the air permeability
test is almost irrelevant. The
requirement of PAS 2035
is to assess the existing
ventilation to determine if it is
adequate. If you are proposing
to install any insulation or air
tightness measures, and the ventilation is
deemed inadequate, you must upgrade it.
The upgrade requirements are in PAS 29035
Annex C, and in The Retrofit Academy’s
Ventilation for Retrofit guide. Click here.

I am a Retrofit Coordinator and have been MCIOB for 22 years. I have passed the Level 3 Energy Efficiency for Older and Traditional Buildings and 2-day CIOB Conservation Certification Scheme courses. Would I be eligible to prepare Retrofit Designs for Path B and C traditional and protected buildings based on a ‘working towards’ CIOB Conservation Scheme ‘Proficient’ level status? Who can sign off these designs, as there can literally only be a handful of ‘qualified’ individuals in the country?

Yes, you are eligible to be the
Retrofit Designer for projects in
Path B or Path C because of your
MCIOB status. Your Retrofit
Coordinator qualification also
allows you to be the Retrofit
Designer for Path B projects,
but this is being withdrawn
as part of the current PAS 2035 amendment.
Unfortunately you are not eligible to be the
Retrofit Designer for Path B or Path C projects
involving traditionally constructed or protected
buildings because PAS 2035 does not include a
‘working towards’ concession for the required
conservation certification or accreditation.

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